Stating the obvious reaches new limits with the Audi RS7 Sportback Performance.

The three-year-old RS7 – and its RS6 Avant near-twin – could have added several new model designations in a bid to boost what came before, but ‘performance’ needed no extra emphasis for this lightning-fast liftback.

Perhaps ‘light’ could have been used to represent some subtraction from its two-tonne weight, or ‘stripper’ to denote a removal of some luxury equipment and price reduction – although rival BMW already uses the euphemism ‘pure’ for these models.

Instead Audi has increased power and torque, lowering the 0-100km/h acceleration time for a little extra outlay. So how does the RS7 Sportback Performance perform?

OVERVIEW

The 4.0-litre twin-turbocharged V8 engine powering this fattened RS now makes 445kW of power between 6100rpm and 6800rpm, up from the original’s 412kW produced over 5700rpm to 6700rpm.

Identical torque of 700Nm is now made over a staggeringly broad 1750rpm to 6000rpm (previously to 5500rpm), but this Audi engine can also now deliver 750Nm on brief overboost inside a 2500rpm to 5500rpm window.

With an eight-speed automatic driving all four wheels – typically with 60 per cent of drive sent rearwards – shod in 275mm-wide 21-inch tyres, the upshot is a sizeable five-door liftback that can accelerate 0-100km/h in 3.7 seconds. The previous claim was 3.9sec.

New exterior styling detail separates the superseded RS7 Sportback from its new RS7 Sportback Performance replacement, although a keen eye will be required to spot the difference. A well-stocked wallet is also needed to load this Audi with the chassis technology and cabin kit befitting of its lower-case-p performance.

The original A7 Sportback – on which the RS7 Sportback is based – made its global debut in 2011, so (as is often the case) it’s a testament to Audi designers and engineers that the cabin has held up so well.

From its soft-touch plastics to its gentle mood lighting and interplay of tones and textures, the interior feels befitting of a $200K-plus vehicle.

Newer Audi models such as the A4 and TT show up this (much) more expensive sibling with their ‘virtual cockpit’ design that replaces the analogue speedometer and tachometer cluster with an enormous TFT colour screen.

However, the high-resolution 8.0-inch colour screen works beautifully with the knurled-silver knobs of Audi’s Multi-Media Interface (MMI) infotainment controller, and the smaller colour screen ahead of the driver still acts a superb model of simplicity; nav, media, phone, driver assistance and trip computer functions can all be accessed easily, without hands leaving the steering wheel.

Standard RS sports seats are covered in cossetting premium leather with honeycomb stitching, and are electrically adjustable and heated. At this price, a cooling function is expected though.

Likewise, the standard Bose audio system was on our test car flicked for a supreme – and supremely expensive at $12,000 – Bang and Olufsen unit, while soft-close power doors add a further $1400 and night vision assistance is $4890 extra.

Rear passengers will enjoy the four-zone climate control function, but the lack of a middle seatbelt is a disappointing for a large touring sedan-cum-liftback. Legroom is reasonably impressive, but headroom is restricted due to that sloping roofline.

In fact, the RS7 Sportback Performance is more impressively packaged in terms of luggage space and practicality than for rear riders. With an impressive 535 litres of boot volume accessed via an electrically raised liftback and wide aperture, it’s only 30L short of its big-bummed RS6 Avant wagon cousin. That model also seats three across the rear with space to spare, particularly for taller people.

ON THE ROAD

Engine: 445kW/700Nm 4.0 V8 twin-turbo petrol

Transmission: eight-speed automatic, AWD

Suspension: multi-link independent front and rear

Brake: carbon ceramic ventilated front and rear disc brakes

Steering: electrically assisted mechanical steering

Outright performance is not the most impressive aspect about the RS7 Sportback Performance, thrilling though it is. Nor does its handling rate as the virtue that most stands out. Even the brakes – the optional ceramic disc units fitted here are described as “indefatigable” by Audi – come a close second.

Rather it is the Clark Kent-to-Superman segue between comfort and control, refinement and riotous behaviour, that will leave a driver’s jaw bumping the bottom of the steering wheel in the RS7 Sportback Performance.

Driving between Sydney and Canberra for this test – a slightly uphill leg – the Audi averaged 9.2 litres per 100 kilometres according to the trip computer. Sounds impressive, right? Well, on the return leg it figured 7.6L/100km. The V8 is silent on the freeway and regularly shuts down four cylinders on light load.

With adaptive cruise, lane-keep assistance and Matrix LED headlights with adaptive high-beam – which can detect forward or oncoming cars and cancel only the portion of beam affecting those drivers – the RS7 Sportback Performance behaves exactly as a luxury car should on such a drive.

There is some coarse-chip road roar, but only a slight amount thanks to those fat tyres, perhaps to remind the driver this isn’t an A7 Sportback 3.0 TDI diesel.

The three-mode suspension only reveals the barest hint of body float in Comfort, and yet it nibbles at the surface in Auto. But considering the ultra-low-profile tyres at play, making a complaint here is like whingeing that a fraction too much summer sun is filtering into the corporate box at the cricket as Veuve Clicquot is being sipped.

On the following drive loop through the Brindabella Ranges in the nation’s capital, the RS7 Sportback Performance then switched characters effortlessly but intensely. The optional RS Dynamic Plus suspension uses steel springs with the adaptive dampers inter-connected via diagonal oil lines and a central valve to quell bodyroll.

In concert with the variable-ratio ‘dynamic’ steering that comes with that option, and those brakes, this Audi adopts a tight and forthright disposition through corners. The V8 engine blasts off sounding like a departing Boeing 747 as a rush of burnt fuel leaves the quad tailpipes that then crackle and pop on overrun.

The auto is virtually flawless and the steering is almost electric on turn-in; which as with the suspension’s character, presents a staggering contrast given how stable and fluent the system is on the freeway.

Stand on the brakes late through a pedal that feels almost as though it’s pushing back – such is its firm response – and suddenly a sizeable portion of the 2005kg kerb weight is pushed over the front axle, burrowing the front 21s into the ground.

In really tight corners, holding onto the brakes longer than usual on turn-in unloads weight to the outside back wheel of this extremely heavy weapon. The variable all-wheel drive system then permits immediate and hard throttle on corner exit.

There is rarely understeer, and only occasional oversteer, and anything further should be left for racetrack work. Tellingly, the ESC Sport mode did not activate once despite this sizeable liftback snaking down several 90-degree turns on a tight pass.

Only a little less weight, and perhaps a little extra drive to the rear wheels more often, could improve this staggeringly superb super-sports model.

WARRANTY AND SERVICING

RIVALS TO CONSIDER

All rivals are in a holding pattern – a new M5 is set for global debut soon, the E63 S arrives next year with a 3.4sec 0-100km/h and an all-wheel drive system that can deactivate front-drive to allow oversteer slides; and Volkswagen Group sibling the Porsche Panamera Turbo is imminent, but wildly expensive.

TMR VERDICT | OVERALL

For now, the Audi RS7 Sportback Performance virtually has the market to itself. Forget semantics, because what this updated model does is prime the ageing model for combat with the next E63 S first, then the next M5 later.

In the ways that count, however, this flagship five-door liftback doesn’t feel aged at all. Perhaps it could be a fraction lighter, with some newer cabin technology and equipment such as the high-end stereo as standard.

However, even with options that take the price from $258,000 to $300,000, it delivers multiple virtues to such a high standard, effortlessly switching between comfortable executive express and jaw-dropping corner carver – indeed, why buy a luxury car when this model can do luxury and sports equally well?

If the rear seat is compromised in the name of style, then there is always the RS6 Avant Performance that would be our pick of Audi’s high-performance duo. It’s a win-win – at least until newer rivals arrive.